JP2005269600A - Image processor and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optionally correct a place of a desired hue and saturation in a video signal in real time in accordance with the hue and saturation. <P>SOLUTION: An image processor is provided with an extracting means 2 for extracting a hue and saturation from an input video signal in real time, a determination means 3 for determining a correction amount of the input video signal in real time in accordance with the hue and saturation extracted by the extracting means 2, and a correction means 4 for correcting the input video signal in real time on the basis of the determination result of the determination means 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image processing apparatus and an image processing method for correcting hue and saturation of a video signal.

  In general, video equipment such as a television receiver and a television camera is equipped with a device for correcting the hue and saturation of a video signal for the purpose of color adjustment and the like.

  Conventionally, as a device for correcting the hue of a video signal, two color difference signals are respectively subjected to color difference conversion by a color difference conversion matrix circuit, and each of the two color difference signals subjected to the color difference conversion is sliced. There is one in which a color region to be corrected is extracted by taking a minimum value (see, for example, Patent Document 1). )

  FIG. 8 is a block diagram showing a configuration example of a portion of the color signal extraction circuit of such a hue correction apparatus. Of the color difference signal Cb (= BY) and color difference signal Cr (= RY) input to the color signal extraction circuit, the color difference signal Cb is supplied to the variable gain amplifiers 51 and 52, respectively, and the color difference signal Cr is variable. It is supplied to the gain amplifiers 53 and 54, respectively. The output of the variable gain amplifier 51 and the output of the variable gain amplifier 53 are added by an adder 55, and the output of the variable gain amplifier 52 and the output of the variable gain amplifier 54 are added by an adder 56.

  These variable gain amplifiers 51 to 54 and adders 55 and 56 constitute a color difference conversion matrix circuit 50. The color difference signal Cb ′ subjected to color difference conversion is output from the adder 55 and the color difference signal Cr ′ subjected to color difference conversion. Is output from the adder 56.

  The color difference signal Cb 'and the color difference signal Cr' are input to the maximum value input extraction circuits 57 and 58, respectively. In addition to the color difference signal Cb 'and the color difference signal Cr', a coefficient signal having a predetermined value is input to the maximum value input extraction circuits 57 and 58, respectively. The maximum value input extraction circuits 57 and 58 each extract a maximum value signal of two input signals, and function as a circuit for slicing the color difference signal Cb ′ and the color difference signal Cr ′.

  The output signal of the maximum value input extraction circuit 57 is input to the minimum value input extraction circuit 61 after the input coefficient signal to the maximum value input extraction circuit 57 is subtracted by the subtractor 59. The output signal of the maximum value input extraction circuit 58 is also input to the minimum value input extraction circuit 61 after the subtractor 60 subtracts the input coefficient signal to the maximum value input extraction circuit 58.

  The minimum value input extraction circuit 61 is a circuit that extracts a minimum value signal of two input signals. The output signal of the minimum value input extraction circuit 61 is an extracted color signal obtained by extracting the color area to be corrected.

  FIG. 9 is a diagram illustrating color areas extracted by the color signal extraction circuit of FIG. 8 on a color difference plane in which the color difference signal Cb and the color difference signal Cr are taken on the x axis and the y axis, respectively. By adjusting the gains of the variable gain amplifiers 51 to 54, a region A11 sandwiched between a half line b1 whose angle with respect to the x axis is θ1 and a half line b2 whose angle with respect to the x axis is θ2 is corrected. Extracted as a color area. A half line bm whose angle with respect to the x-axis is θm is a place where the extracted color signal is maximum.

FIG. 10 is a diagram in which the extracted color signal output from the minimum value input extraction circuit 61 for the color region shown in FIG. 9 is plotted three-dimensionally (the extracted color signal is taken on the Z axis). The extracted color signal increases as the distance from the origin of the color difference plane increases (that is, as the saturation increases), but in the angle direction (hue direction) of the color difference plane, the same curve is drawn regardless of the saturation.
JP-A-11-308628 (paragraph numbers 0012 to 0022, FIGS. 7 and 8)

  Incidentally, in recent years, when performing color adjustment or the like, there is an increasing need to arbitrarily correct a desired hue and saturation portion of a video signal in accordance with the hue and saturation.

  However, in the conventional hue correction apparatus as shown in FIG. 8, it is difficult to meet such needs from the following points (a) to (c).

  (A) As shown in FIG. 11, the values of the angles θ1 and θ2 shown in FIG. 9 are between the half line b1 and the half line b2, and the x axis or y axis (the angle with respect to the x axis is 0 °, 90 If the value is such that there is a position where the angle is 180 ° or 180 ° or 270 °, it is difficult to specify a region sandwiched between the half line b1 and the half line b2, and thus it is difficult to extract a color region. become.

  Further, when the difference between θ1 and θ2 exceeds 90 °, the x-axis or the y-axis always exists between the half line b1 and the half line b2. For this reason, it is difficult to extract a large color region in which the difference between θ1 and θ2 exceeds 90 °.

  As described above, since a color region that can be extracted as a correction target is restricted, it is difficult to correct a desired hue location in the video signal.

  (B) By adjusting the gains of the variable gain amplifiers 51 to 54 in FIG. 8, not only the color region to be extracted is determined, but also the level of the extracted color signal (and thus the extracted color) as shown in FIG. The degree of correction for the region is also determined. In this way, the color difference conversion matrix circuit 50 that determines the color region to be corrected also serves as a circuit that determines the correction amount, so that the video signal can be arbitrarily corrected (for example, the hue and saturation of the video signal are determined). It is difficult to correct them independently of each other.

  (C) The color signal extraction circuit of FIG. 8 can extract only one color region as illustrated in FIG. Therefore, for example, when two or more color areas are extracted and corrected respectively as shown as areas A11 and A12 in FIG. 12, it is necessary to provide two or more color signal extraction circuits in FIG. This increases the circuit scale.

  In view of the above, the present invention provides an image processing apparatus and an image processing method that can arbitrarily correct a desired hue and saturation portion of a video signal according to the hue and saturation. It was made as an issue.

  In order to solve this problem, an image processing apparatus according to the present invention is an image processing apparatus that corrects the hue and saturation of an input video signal in real time, and extracts the hue and saturation from the input video signal. Means, a determining means for determining a correction amount according to the hue and saturation extracted by the extracting means, and a correcting means for correcting the hue and saturation of the input video signal based on the determination result of the determining means It is characterized by comprising.

  In this image processing apparatus, the hue and the saturation are respectively extracted in real time from the input video signal by the extracting means. Then, the correction means according to the extracted hue and saturation is determined in real time by the determining means. Based on the determination result, the hue and saturation of the input video signal are corrected in real time by the correcting means.

  Thus, by extracting the hue and saturation of the input video signal, and determining the correction amount according to the extracted hue and saturation, the desired hue and saturation of the input video signal are determined. Can be arbitrarily corrected in real time according to the hue and saturation.

  In addition, what is necessary is just to comprise the extraction means of this image processing apparatus as an example so that a hue and saturation may be extracted from two input color difference signals using an arctangent.

  In this image processing apparatus, as an example, it is preferable that the determining means determines the correction amount so that the input video signal is corrected for a plurality of regions having different hues. As a result, correction can be performed for two or more color regions without increasing the circuit scale.

  Further, in this image processing apparatus, as an example, it is preferable that the determining unit determines the hue correction amount and the saturation correction amount of the input video signal independently of each other. As a result, the hue and saturation of the video signal can be corrected independently of each other (correcting only the hue, correcting only the saturation, or correcting the hue and saturation by different amounts). Become.

  In this image processing apparatus, as an example, it is preferable that the determining means determines the correction amount over the entire angle range on the color difference plane where the two color difference signals are taken on the x axis and the y axis. It is. Thereby, a color region including a portion where the angle with respect to the x axis is 0 °, 90 °, 180 ° or 270 ° on the color difference plane, or a color region having an angle range with respect to the x axis exceeding 90 ° on the color difference plane. It becomes possible to perform correction for.

  In this image processing apparatus, as an example, it is preferable that the correction unit corrects the input video signal based on not only the determination result of the determination unit but also the luminance level of the input video signal. This makes it possible to arbitrarily correct a desired hue and saturation location in the video signal according to not only the hue and saturation but also the luminance level of the video signal.

  Next, an image processing method according to the present invention is an image processing method for correcting the hue and saturation of an input video signal in real time, the first step of extracting the hue and saturation from the input video signal, A second step for determining a correction amount corresponding to the hue and saturation extracted in the first step, and the hue and saturation of the input video signal are corrected based on the determination result of the second step. And a third step.

  According to this image processing method, the hue and saturation of the input video signal are extracted, and the correction amount corresponding to the extracted hue and saturation is determined, so that the desired hue and saturation of the input video signal are determined. The location of the degree can be arbitrarily corrected in real time according to the hue and saturation.

  According to the present invention, the hue and saturation of the input video signal are extracted, and the correction amount corresponding to the extracted hue and saturation is determined. There is an effect that the portion of saturation can be arbitrarily corrected in real time according to the hue and saturation.

  Further, by determining the correction amount so that the input video signal is corrected for a plurality of regions having different hues, it is possible to perform correction for two or more color regions without increasing the circuit scale. Can also be obtained.

  Also, by determining the hue correction amount and saturation correction amount of the input video signal independently of each other, the hue and saturation of the video signal are corrected independently of each other (correcting only the hue or saturation). It is possible to obtain an effect that the hue and the saturation can be corrected by different amounts).

  Further, by determining the correction amount over the entire angle range on the color difference plane with the two color difference signals taken on the x axis and the y axis, the angles with respect to the x axis on this color difference plane are 0 °, 90 °, There is also an effect that correction can be performed for a color region including a portion at 180 ° or 270 °, or a color region whose angle range with respect to the x axis exceeds 90 ° on the color difference plane.

  In addition, by correcting the input video signal based on the luminance level of the input video signal as well as the correction amount determined according to the extracted hue and saturation, a desired hue and saturation of the video signal can be obtained. There is also an effect that the portion can be arbitrarily corrected according to not only the hue and saturation but also the luminance level of the video signal.

  Hereinafter, the present invention will be specifically described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of an image processing apparatus to which the present invention is applied. This image processing apparatus is provided in a digital television broadcast receiving apparatus, and a digital video signal subjected to processing such as digital demodulation, error correction, demultiplexing, and decoding by frequency selection by a tuner (not shown) is provided. Are input to the image input unit 1.

  When the video signal RGB of the three primary colors is input, the image input unit 1 converts the video signal RGB into a component signal YCbCr, and separates the luminance signal Y and the color difference signals Cb and Cr from the component signal YCbCr. It is a circuit to output. (When the component signal YCbCr is input, the luminance signal Y and the color difference signals Cb and Cr are simply separated from the component signal YCbCr and output.)

  The color difference signals Cb and Cr output from the image input unit 1 are sent to the color extraction unit 2 and the color correction unit 4. The luminance signal Y output from the image input unit 1 is sent to the color correction unit 4.

  The color extraction unit 2 is a circuit that extracts hue and saturation from input color difference signals Cb and Cr. FIG. 2 shows the configuration of the color extraction unit 2. The color extraction unit 2 includes a calculation unit 11, an LUT (lookup table) 12, and a calculation unit 13. The color difference signals Cb and Cr input to the color extraction unit 2 are sent to the calculation unit 11 and the calculation unit 13.

  The calculation unit 11 is an arithmetic circuit that calculates a ratio Cr / Cb of the level of the color difference signal Cr to the level of the color difference signal Cb for each pixel clock with respect to the input color difference signals Cb and Cr. A signal indicating the ratio Cr / Cb calculated by the calculation unit 11 is sent to the LUT 12.

  The LUT 12 includes a ROM that stores the ratio Cr / Cb value and the arc tangent Cr / Cb value in association with each other, and the arc tangent Cr corresponding to the input ratio Cr / Cb value for each pixel clock. A signal θ indicating the value of / Cb is read from this ROM and output.

  FIG. 3 shows the value θ1 of the output signal θ of the LUT 12 when the color difference signals Cb and Cr are at certain levels Cb1 and Cr1, respectively, on the color difference plane where the color difference signals Cb and Cr are taken on the x axis and the y axis, respectively. FIG. As illustrated in FIG. 3, the output signal θ of the LUT 12 represents the hue of the input video signal to the image processing apparatus.

  The calculation unit 13 is an arithmetic circuit that calculates the size of the vector (Cb, Cr) on the color difference plane of FIG. 3 for each pixel clock from the input color difference signals Cb, Cr. The signal Sa shown is output. As shown in FIG. 3, when the color difference signals Cb and Cr are level Cb1 and Cr1, respectively, the magnitude Sa1 of the vector (Cb1 and Cr1) is calculated by the calculation unit 13. As illustrated in FIG. 3, the output signal Sa of the calculation unit 13 represents the saturation of the input video signal to the image processing apparatus.

  As shown in FIG. 1, the color extraction unit 2 sends the output signal θ of the LUT 12 and the output signal Sa of the calculation unit 13 (signals indicating the hue and saturation of the input video signal) to the color correction amount determination unit 3. It is done.

  The color correction amount determination unit 3 is a circuit that determines a correction amount according to the hue and saturation extracted by the color extraction unit 2 by referring to a correction amount lookup table in factory settings. For example, for an input video signal in a hue range corresponding to a flesh color, the hue correction amount is slightly reddish, and at the same time, the correction amount is conspicuous by slightly increasing the saturation. Also, a plurality of correction amount lookup tables may be provided so that the correction amount can be selected by, for example, user mode switching. FIG. 4 shows the configuration of the color correction amount determination unit 3. The color correction amount determination unit 3 includes a correction amount calculation unit 14 and a correction amount calculation unit 15. Both the signal θ and the signal Sa input to the color correction amount determination unit 3 are sent to the correction amount calculation unit 14 and the correction amount calculation unit 15.

  The correction amount calculation unit 14 refers to, for example, a correction amount lookup table for each pixel clock from the value of the signal θ and the value of the signal Sa, thereby correcting the hue correction amount for the input video signal to the image processing apparatus. It is an arithmetic circuit that determines (amount of increase / decrease relative to the original hue), and outputs a signal Δθ indicating the determined correction amount.

  The correction amount calculation unit 15 refers to, for example, a correction amount lookup table for each pixel clock from the value of the signal θ and the value of the signal Sa, thereby correcting the saturation for the video signal input to the image processing apparatus. This is an arithmetic circuit that determines the amount (magnification with respect to the original saturation), and outputs a signal Sg indicating the determined correction amount. An image processing apparatus to which the present invention is applied is an image processing apparatus that corrects the hue and saturation of an input video signal in real time, and includes a color extraction unit 2, a color correction amount determination unit 3, and a color correction shown in FIG. The processing of the unit 4 is performed in real time.

  FIG. 5 shows that when the value of the signal Sa is a fixed value, the value of the signal Δθ calculated by the correction amount calculation unit 14 and the value of the signal Sg calculated by the correction amount calculation unit 15 are It is a figure which shows a mode that it changes with the change of a value. When the fixed values are different values, the values of these signals Δθ and Sg can be different.

  As shown in FIG. 5A, the value of the signal Δθ calculated by the correction amount calculation unit 14 (hue correction amount) includes a portion where the angle with respect to the x-axis is 90 ° on the color difference plane of FIG. In the color region A1, the increase / decrease amount is positive. In this color difference plane, the increase / decrease amount is negative in the color region A2 (the color region where the angle range with respect to the x axis exceeds 90 °) including the location where the angle with respect to the x axis is 180 ° and the location where the angle is 270 °. . In other color regions, the increase / decrease amount is set to zero.

  As shown in FIG. 5B, the value of the signal Sg (saturation correction amount) calculated by the correction amount calculation unit 15 is a point where the angle with respect to the x axis is 90 ° on the color difference plane of FIG. In the including color region A3, the magnification is set to be larger than 1. In addition, the magnification is less than 1 in the color region A4 including a portion where the angle with respect to the x axis is 180 ° on the color difference plane. In other color areas, the magnification is set to 1.

  In this way, in the color correction amount determination unit 3, the correction amount calculation unit 14 and the correction amount calculation unit 15 determine the hue correction amount and the saturation correction amount of the input video signal independently of each other.

  Further, as illustrated in FIG. 5, the correction amount calculation unit 14 and the correction amount calculation unit 15 respectively correct the correction amount over the entire angle range (0 ° to 360 °) on the color difference plane illustrated in FIG. 3. And the amount of correction is determined so that the input video signal is corrected in a plurality of regions having different hues (two regions A1, A2, A3, and A4 in FIG. 5).

  As shown in FIG. 1, the color correction amount determination unit 3 sends a signal Δθ indicating the hue correction amount and a signal Sg indicating the saturation correction amount to the color correction unit 4.

  The color correction unit 4 is a circuit that corrects an input video signal to the image processing apparatus based on the determination result of the correction amount in the color correction amount determination unit 3. FIG. 6 shows the configuration of the color correction unit 4. The color correction unit 4 includes a luminance dependency adjustment unit 16 and a hue / saturation adjustment unit 17. The signal Δθ and the signal Sg input from the color correction amount determination unit 3 to the color correction unit 4 are sent to the luminance dependence adjustment unit 16. As shown in FIG. 1, the luminance signal Y input from the image input unit 1 to the color correction unit 4 is sent to the luminance dependency adjustment unit 16 and is output from the color correction unit 4 as it is.

  The luminance dependence adjustment unit 16 is an arithmetic circuit that adjusts the levels of the signals Δθ and Sg according to the level of the luminance signal Y for each pixel clock, and adjusts the signal Δθ2 indicating the correction amount of the adjusted hue. A signal Sg2 indicating the saturation correction amount is output.

  FIG. 7 shows a state where the levels of the signal Δθ and the signal Sg illustrated in FIG. 5 are adjusted by the luminance dependence adjusting unit 16 when the level of the luminance signal Y is relatively low. As in the example of FIG. 7, when the level of the luminance signal Y is relatively low (in the case of a dark scene), the luminance dependency adjustment unit 16 prevents the signal Δθ, The level of the signal Sg is suppressed.

The signal Δθ2 and the signal Sg2 output from the luminance dependence adjustment unit 16 are sent to the hue / saturation adjustment unit 17. As shown in FIG. 1, the color difference signals Cb and Cr input from the image input unit 1 to the color correction unit 4 are also sent to the hue saturation adjustment unit 17. The hue / saturation adjustment unit 17 is an arithmetic circuit that performs matrix processing for adjusting the hue and saturation of the color difference signals Cb and Cr for each pixel clock using the signal Δθ2 and the signal Sg2 according to the following equations. The color difference signals Cb2 and Cr2 are output. The matrix processing itself is processing that is generally performed by a television receiver or the like.

  As shown in FIG. 1, the color correction unit 4 sends the color difference signals Cb <b> 2 and Cr <b> 2 output from the hue saturation adjustment unit 17 and the luminance signal Y to the image output unit 5. The image output unit 5 converts these color difference signals Cb2, Cr2 and Y into video signals RGB of three primary colors and sends them to a display (for example, a plasma display panel) 6.

  As described above, in this image processing apparatus, the hue and saturation are extracted from the input video signal by the color extraction unit 2 in real time. Then, the color correction amount determination unit 3 determines the correction amount according to the extracted hue and saturation in real time. Based on the determination result, the hue and saturation of the input video signal are corrected in real time by the color correction unit 4.

  Thus, by extracting the hue and saturation of the input video signal, and determining the correction amount according to the extracted hue and saturation, the desired hue and saturation of the input video signal are determined. Can be arbitrarily corrected in real time according to the hue and saturation.

  In addition, since the hue correction amount determination unit 3 determines the hue correction amount and the saturation correction amount of the input video signal independently of each other, the hue and saturation of the video signal are corrected independently of each other (hue) Only correction, correction of saturation, or correction of hue and saturation by different amounts).

  In addition, since the color correction amount determination unit 3 determines the correction amount so that the input video signal is corrected for a plurality of regions having different hues, correction is performed for two or more color regions without increasing the circuit scale. It can be carried out.

  Further, since the correction amount determination unit 3 determines the correction amount over the entire angle range (0 ° to 360 °) on the color difference plane of FIG. 3, as illustrated in FIG. Correction can also be performed for a color region including a portion where the angle with respect to the axis is 0 °, 90 °, 180 °, or 270 °, or a color region whose angle range with respect to the x-axis exceeds 90 ° on this color difference plane.

  In addition, since the color correction unit 4 corrects the input video signal based on not only the determination result of the correction amount determination unit 3 but also the luminance level of the input video signal, a desired hue and saturation portion of the video signal is determined. The correction can be arbitrarily made according to not only the hue and saturation but also the luminance level of the video signal.

  In the above example, the calculation unit 13 of the color extraction unit 2 calculates the size of the vector (Cb, Cr) on the color difference plane of FIG. However, in order to calculate the magnitude of the vector (Cb, Cr), square and square root calculations are required. In this embodiment, the video signal is a moving image, and these calculations are performed in real time for each pixel clock. Therefore, the calculation unit 13 may calculate an approximate value of the size of the vector (Cb, Cr) in order to reduce the burden of such calculation processing.

  In the above example, the color extracting unit 2 extracts the hue of the input video signal using a lookup table and extracts the saturation of the input video signal using an arithmetic circuit. However, the present invention is not limited to this, and the hue of the input video signal may be extracted using an arithmetic circuit, or the saturation of the input video signal may be extracted using a lookup table. Similarly, the color correction amount determination unit 3 may determine the hue and saturation correction amounts using a lookup table instead of the arithmetic circuit.

  In the above example, the present invention is applied to a television broadcast receiver. However, the present invention is not limited to this, and the present invention may be applied to an imaging device such as a television camera, a video recording / reproducing device such as a DVD player, an editing device, and the like.

1 is a block diagram illustrating an overall configuration of an image processing apparatus to which the present invention is applied. It is a block diagram which shows the structure of the color extraction part of FIG. It is a figure which illustrates the hue and saturation which are extracted by the color extraction part. FIG. 2 is a block diagram illustrating a configuration of a color correction amount determination unit in FIG. 1. It is a figure which illustrates the correction amount determined by the color correction amount determination unit. It is a block diagram which shows the structure of the color correction part of FIG. It is a figure which illustrates the process of the brightness | luminance dependence adjustment part of FIG. It is a block diagram which shows the structural example of the conventional color signal extraction circuit. It is a figure which illustrates the color area extracted by the color signal extraction circuit of FIG. FIG. 10 is a diagram illustrating an extracted color signal output from the color signal extraction circuit of FIG. 8 for the color region of FIG. 9. FIG. 10 is a diagram illustrating an example in which a y-axis exists between the half lines b1 and b2 in FIG. 9. It is a figure which shows the example which is going to extract two color area | regions.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image input part 2 Color extraction part 3 Color correction amount determination part 4 Color correction part 5 Image output part 6 Display 11 Calculation part 12 LUT
13 Calculation unit 14 Correction amount calculation unit 15 Correction amount calculation unit 16 Luminance dependence adjustment unit 17 Hue / saturation adjustment unit

Claims (12)

An image processing device that corrects the hue and saturation of an input video signal in real time,
Extraction means for extracting hue and saturation from the input video signal;
Determining means for determining a correction amount according to the hue and saturation extracted by the extracting means;
An image processing apparatus comprising: a correction unit that corrects the hue and saturation of the input video signal based on a determination result of the determination unit. The image processing apparatus according to claim 1.
The image processing apparatus is characterized in that the extraction means extracts hue and saturation from two input color difference signals using arctangent. The image processing apparatus according to claim 1.
The image processing apparatus according to claim 1, wherein the determining unit determines a correction amount so that the input video signal is corrected for a plurality of regions having different hues. The image processing apparatus according to claim 1.
The image processing apparatus according to claim 1, wherein the determination unit determines a hue correction amount and a saturation correction amount of the input video signal independently of each other. The image processing apparatus according to claim 1.
The determination means determines an amount of correction over the entire angle range on a color difference plane in which two color difference signals are taken on the x axis and the y axis. The image processing apparatus according to claim 1.
The image processing apparatus, wherein the correction unit corrects the input video signal based on a determination result of the determination unit and a luminance level of the input video signal. An image processing method for correcting the hue and saturation of an input video signal in real time,
A first step of extracting hue and saturation from the input video signal;
A second step of determining a correction amount according to the hue and saturation extracted in the first step;
And a third step of correcting the hue and saturation of the input video signal based on the determination result of the second step. The image processing method according to claim 7.
In the first step, the hue and the saturation are extracted from the two input color difference signals using arctangent. The image processing method according to claim 7.
An image processing method characterized in that, in the second step, a correction amount is determined so that the input video signal is corrected for a plurality of regions having different hues. The image processing method according to claim 7.
In the second step, the hue correction amount and the saturation correction amount of the input video signal are determined independently of each other. The image processing method according to claim 7.
An image processing method characterized in that, in the second step, a correction amount is determined over all angle ranges on a color difference plane in which two color difference signals are taken on the x axis and the y axis. The image processing method according to claim 7.
In the third step, the input video signal is corrected based on the determination result of the second step and the luminance level of the input video signal.

Images